<template>
  <div class="type-nav">
    <div class="container">
      <div @mouseleave="hideSubList" @mouseenter="showFirst">
        <h2 class="all">全部商品分类</h2>
        <transition name="showFirst">
          <div class="sort" v-show="isFirstShow">
            <div class="all-sort-list2" @click="toSearch">
              <div
                class="item"
                v-for="(c1, index) in crategoryList"
                :key="c1.catId"
                :class="{ active: currentIndex === index }"
                @mouseenter="showSubList(index)"
              >
                <h3>
                  <a
                    href="javascript:;"
                    :data-categroyname="c1.name"
                    :data-categroy1id="c1.catId"
                    >{{ c1.name }}</a
                  >
                  <!-- 声明式导航  缺点 会产生过多的组件 -->
                  <!-- <router-link :to="`/search?categroyname=${c1.name}&categroyid=${c1.catId}`" >{{c1.name}}</router-link> -->
                </h3>
                <div class="item-list clearfix">
                  <div class="subitem">
                    <dl class="fore" v-for="c2 in c1.children" :key="c2.catId">
                      <dt>
                        <a
                          href="javascript:;"
                          :data-categroyName="c2.name"
                          :data-categroy1id="c2.catId"
                          >{{ c2.name }}</a
                        >
                        <!-- <a @click="$router.push(`/search?categroyname=${c2.name}&categroyid=${c2.catId}`)">{{ c2.name }}</a> -->
                      </dt>
                      <dd>
                        <em v-for="c3 in c2.children" :key="c3.catId">
                          <a
                            href="javascript:;"
                            :data-categroyName="c3.name"
                            :data-categroy1id="c3.catId"
                            >{{ c3.name }}</a
                          >
                        </em>
                      </dd>
                    </dl>
                  </div>
                </div>
              </div>
            </div>
          </div>
        </transition>
      </div>
      <nav class="nav">
        <a href="###">服装城</a>
        <a href="###">美妆馆</a>
        <a href="###">尚品汇超市</a>
        <a href="###">全球购</a>
        <a href="###">闪购</a>
        <a href="###">团购</a>
        <a href="###">有趣</a>
        <a href="###">秒杀</a>
      </nav>
    </div>
  </div>
</template>

<script>
// import { mapState } from 'vuex';
// import _ from 'lodash'
import throttle from "lodash/throttle";
export default {
  name: "TypeNav",
  data() {
    return {
      currentIndex: -2,
      isFirstShow: false,
    };
  },
  created() {
    //如果在mounted显示 那会导致页面多更新了一次
    //判断当前请求的是否是首页，如果是 显示
    const path = this.$route.path;
    if (path === "/") {
      this.isFirstShow = true;
    }
  },
  methods: {
    //显示一级列表
    showFirst() {
      //这个是鼠标移入的更改 表示当前已经进入包含分类的div了
      this.currentIndex = -1;
      this.isFirstShow =true;
    },
    hideSubList() {
      this.currentIndex = -2;
      if(this.$route.path !== '/'){
        this.isFirstShow=false
      }
    },
    showSubList: throttle(function (index) {
      //这个时间监听回调函数调用的频率太高
      //只有当还没离开整个分类的div时才更新
      if (this.currentIndex !== -2) {
        this.currentIndex = index;
      }
      // r如果这样写会有一个新的问题
    }, 200), //{trailing:false})

    //事件委派  点击带上参数问题
    toSearch(event) {
      const target = event.target;
      //使用了dataset
      const { categroyname, categroy1id, categroy2id, categroy3id } =
        event.target.dataset;
      console.log(categroyname, categroy1id);
      console.dir(target);
      if (categroyname) {
        const query = {
          categroyName: categroyname,
        };
        if (categroy1id) {
          query.categroyId = categroy1id;
        } else if (categroy2id) {
          query.categroyId = categroy2id;
        } else if (categroy3id) {
          query.categroyId = categroy3id;
        }
        
        //准备一个用于调转的对象
        const location={
          //可以写命名路由
          name: "search",
          // path:'/search',
          query,
          params:this.$route.params
        }
        this.$router.push(location);
      }
    },
  },
  computed: {
    crategoryList() {
      return this.$store.state.home.crategoryList;
    },
    
    //  ...mapState({
    //    categoryList : state => state.home.categoryList
    //  })
    // categoryList: state => state.home.categoryList,
  },
};
</script>

<style lang='less' scoped>
.type-nav {
  border-bottom: 2px solid #e1251b;

  .container {
    width: 1200px;
    margin: 0 auto;
    display: flex;
    position: relative;

    .all {
      width: 210px;
      height: 45px;
      background-color: #e1251b;
      line-height: 45px;
      text-align: center;
      color: #fff;
      font-size: 14px;
      font-weight: bold;
    }

    .nav {
      a {
        height: 45px;
        margin: 0 22px;
        line-height: 45px;
        font-size: 16px;
        color: #333;
      }
    }

    .sort {
      &.showFirst-enter-active,&.showFirst-leave-active{
        transition: all .3s;
      }
      &.showFirst-enter,&.showFirst-leave-to{
        opacity: 0;
        height: 0;
      }
      position: absolute;
      left: 0;
      top: 45px;
      width: 210px;
      height: 461px;
      position: absolute;
      background: #fafafa;
      z-index: 999;

      .all-sort-list2 {
        .item {
          h3 {
            line-height: 30px;
            font-size: 14px;
            font-weight: 400;
            overflow: hidden;
            padding: 0 20px;
            margin: 0;

            a {
              color: #333;
            }
          }

          .item-list {
            display: none;
            position: absolute;
            width: 734px;
            min-height: 460px;
            background: #f7f7f7;
            left: 210px;
            border: 1px solid #ddd;
            top: 0;
            z-index: 9999 !important;

            .subitem {
              float: left;
              width: 650px;
              padding: 0 4px 0 8px;

              dl {
                border-top: 1px solid #eee;
                padding: 6px 0;
                overflow: hidden;
                zoom: 1;

                &.fore {
                  border-top: 0;
                }

                dt {
                  float: left;
                  width: 54px;
                  line-height: 22px;
                  text-align: right;
                  padding: 3px 6px 0 0;
                  font-weight: 700;
                }

                dd {
                  float: left;
                  width: 415px;
                  padding: 3px 0 0;
                  overflow: hidden;

                  em {
                    float: left;
                    height: 14px;
                    line-height: 14px;
                    padding: 0 8px;
                    margin-top: 5px;
                    border-left: 1px solid #ccc;
                  }
                }
              }
            }
          }

          &.active {
            background: #ccc;
            .item-list {
              display: block;
            }
          }
        }
      }
    }
  }
}
</style>